Promoting Tdap immunization in pregnancy: Associations between maternal perceptions and vaccination rates

Interventions to increase vaccination against COVID-19, influenza and pertussis during pregnancy: a systematic review and meta-analysis

BACKGROUND

Pregnant women and their babies face significant risks from three vaccine-preventable diseases: COVID-19, influenza and pertussis. However, despite these vaccines' proven safety and effectiveness, uptake during pregnancy remains low.

METHODS

We conducted a systematic review (PROSPERO CRD42023399488; January 2012-December 2022 following PRISMA guidelines) of interventions to increase COVID-19/influenza/pertussis vaccination in pregnancy. We searched nine databases, including grey literature. Two independent investigators extracted data; discrepancies were resolved by consensus. Meta-analyses were conducted using random-effects models to estimate pooled effect sizes. Heterogeneity was assessed using the I2 statistics.

RESULTS

From 2681 articles, we identified 39 relevant studies (n = 168 262 participants) across nine countries. Fifteen studies (39%) were randomized controlled trials (RCTs); the remainder were observational cohort, quality-improvement or cross-sectional studies. The quality of 18% (7/39) was strong. Pooled results of interventions to increase influenza vaccine uptake (18 effect estimates from 12 RCTs) showed the interventions were effective but had a small effect (risk ratio = 1.07, 95% CI 1.03, 1.13). However, pooled results of interventions to increase pertussis vaccine uptake (10 effect estimates from six RCTs) showed no clear benefit (risk ratio = 0.98, 95% CI 0.94, 1.03). There were no relevant RCTs for COVID-19. Interventions addressed the 'three Ps': patient-, provider- and policy-level strategies. At the patient level, clear recommendations from healthcare professionals backed by text reminders/written information were strongly associated with increased vaccine uptake, especially tailored face-to-face interventions, which addressed women's concerns, dispelled myths and highlighted benefits. Provider-level interventions included educating healthcare professionals about vaccines' safety and effectiveness and reminders to offer vaccinations routinely. Policy-level interventions included financial incentives, mandatory vaccination data fields in electronic health records and ensuring easy availability of vaccinations.

CONCLUSIONS

Interventions had a small effect on increasing influenza vaccination. Training healthcare providers to promote vaccinations during pregnancy is crucial and could be enhanced by utilizing mobile health technologies.

Behavioral interventions for vaccination uptake: A systematic review and meta-analysis

BACKGROUND

Human behavior and more specifically behavioral insight-based approaches to vaccine uptake have often been overlooked. While there have been a few narrative reviews indexed in Medline on behavioral interventions to increase vaccine uptake, to our knowledge, none have been systematic reviews and meta-analyses covering not just high but also low-and-middle income countries.

METHODS

We included 613 studies from the Medline database in our systematic review and meta-analysis categorizing different behavioral interventions in 9 domains: education campaigns, on-site vaccination, incentives, free vaccination, institutional recommendation, provider recommendation, reminder and recall, message framing, and vaccine champion. Additionally, considering that there is variability in the acceptance of vaccines among different populations, we assessed studies from both high-income countries (HICs) and low- to middle-income countries (LMICs), separately.

FINDINGS

Our results showed that behavioral interventions can considerably improve vaccine uptake in most settings. All domains that we examined improved vaccine uptake with the highest effect size associated with provider recommendation (OR: 3.4 (95%CI: 2.5-4.6); Domain: motivation) and on-site vaccination (OR: 2.9 (95%CI: 2.3-3.7); Domain: practical issues). While the number of studies conducted in LMICs was smaller, the quality of studies was similar with those conducted in HICs. Nevertheless, there were variations in the observed effect sizes.

INTERPRETATION

Our findings indicate that "provider recommendation" and "on-site vaccination" along with other behavioral interventions can be employed to increase vaccination rates globally.

Knowledge, Attitudes, and Practices Concerning Maternal Immunization Among Pregnant/Postpartum Women and Health Care Professionals in Peru

INTRODUCTION

For pregnant women, vaccination with inactivated influenza vaccine (IIV) and tetanus, diphtheria, acellular pertussis vaccine (Tdap) is recommended. In Peru, uptake is nonetheless low. A study was conducted to identify factors affecting maternal vaccination coverage. The study's primary objectives were to describe the knowledge, attitudes, and practices regarding maternal immunization among pregnant/postpartum women and health care professionals (HCPs). The secondary objective was to determine the vaccination coverage and the impact of Ministry of Health (MOH) recommendations.

METHODS

An observational multicenter, cross-sectional survey study was conducted from February 1, 2021 to June 30, 2021 in five cities in Peru. Two surveys were conducted to assess knowledge, attitudes, and practices concerning maternal immunization: one among pregnant/postpartum women and one among HCPs.

RESULTS

Participants were 668 pregnant/postpartum women with a mean age of 29.6 years and 219 HCPs-mostly midwives (46.6%) and obstetricians/gynecologists (44.7%). Of the pregnant/postpartum women, 66.9% knew that, in general, vaccinations are given for prevention, and 98.5% believed vaccines are important. Nonetheless, 69.6% of pregnant/postpartum women had poor or moderate knowledge of maternal vaccination. Disease knowledge of influenza (89.1%) and tetanus (87.0%) was high, while knowledge of pertussis (37.7%) was low. Women agreed/strongly agreed that they would get vaccinated with Tdap if a doctor (96.3%), midwife (88.9%), or nurse (72.0%) recommended it. Of the HCPs, 81.3% routinely recommended Tdap vaccination for pregnant women.

CONCLUSIONS

To enhance vaccine acceptance in pregnant women in Peru, we must improve knowledge of the diseases, MOH recommendations, and benefits of the offered vaccinations. HCPs could provide this vaccination knowledge and information along with their vaccination recommendation as the pregnant/postpartum women indicated they would take the vaccines if recommended by their HCPs. Our findings are important for the successful implementation of maternal immunization programs in Peru.

Characteristics associated with influenza vaccination uptake in pregnancy: a retrospective cohort study

BACKGROUND

Pregnant women are at increased risk from influenza, yet maternal influenza vaccination levels remain suboptimal.

AIM

To estimate associations between sociodemographic and health characteristics and seasonal influenza vaccination uptake among pregnant women, and to understand trends over time to inform interventions to improve vaccine coverage.

DESIGN AND SETTING

Retrospective cohort study using linked electronic health records of women in North West London with a pregnancy overlapping an influenza season between September 2010 and February 2020.

METHOD

A multivariable mixed-effects logistic regression model was used to identify associations between characteristics of interest and the primary outcome of influenza vaccination.

RESULTS

In total, 451 954 pregnancies, among 260 744 women, were included. In 85 376 (18.9%) pregnancies women were vaccinated against seasonal influenza. Uptake increased from 8.4% in 2010/11 to 26.4% in 2017/18, dropping again to 21.1% in 2019/20. Uptake was lowest among women aged 15-19 years (11.9%; reference category) or ≥40 years (15.2%; odds ratio [OR] 1.17, 95% confidence interval [CI] = 1.10 to 1.24); of Black (14.1%; OR 0.55, 95% CI = 0.53 to 0.57) or unknown ethnicity (9.9%; OR 0.42, 95% CI = 0.39 to 0.46); who lived in more deprived areas (OR least versus most deprived [reference category] 1.16, 95% CI = 1.11 to 1.21); or with no known risk factors for severe influenza.

CONCLUSION

Seasonal influenza vaccine uptake in pregnant women increased in the decade before the COVID-19 pandemic, but remained suboptimal. Targeted approaches are recommended to reducing inequalities in access to vaccination and should focus on women of Black ethnicity, younger and older women, and women living in deprived areas.

Vaccine uptake and barriers to vaccination among at-risk adult populations in the US

To reduce morbidity and mortality associated with vaccine-preventable diseases (VPD), it is imperative that vaccination programs are implemented and prioritized throughout all stages of life across all populations. This study aimed to determine vaccine uptake and barriers to vaccination against VPDs among at-risk adult populations in the United States. We conducted a systematic literature review for articles published between January 2010 and June 2020 and identified 153 publications. The review identified 17 at-risk populations. Vaccine uptake was suboptimal among many populations, with factors including age, gender, and disease severity, associated with uptake. This review identified several barriers that impact vaccine uptake among at-risk populations, with concerns over safety, vaccine costs, lack of insurance, and lack of provider recommendation commonly reported across populations. Embracing a national life-course immunization framework that integrates developing policies, guidelines, and education would be a step to addressing these barriers.

Models of determinants of COVID-19 vaccine hesitancy in non-pregnant and pregnant population: Review of current literature"

Vaccination has proven to be the most effective tool in controlling the COVID-19 pandemic. While pregnant individuals are considered to be a high-risk population and are more likely to experience adverse effects from COVID-19, vaccination rates among pregnant individuals are significantly lower than in the general population. The Health Belief Model (HBM), Theory of Planned Behavior (TPB), 3C model, 5C model, and 5A model have been used to assess vaccination hesitancy behaviors. In this paper, we review the use of each of these models to address vaccine hesitancy, with a focus on the pregnant population and the COVID-19 vaccine. The HBM, TPB, 3C model, and 5C model have demonstrated great versatility in their ability to evaluate, explain, and modify vaccine hesitancy and behavior. Up to date, the HBM and 3C models appear to be the most effective models to study and address vaccination hesitancy within the pregnant persons.

MomsTalkShots, tailored educational app, improves vaccine attitudes: a randomized controlled trial

BACKGROUND

Many pregnant women and parents have concerns about vaccines. This analysis examined the impact of MomsTalkShots, an individually tailored educational application, on vaccine attitudes of pregnant women and mothers.

METHODS

MomsTalkShots was the patient-level component of a multi-level intervention to improve maternal and infant vaccine uptake that also included provider- and practice-level interventions. The impact of these interventions was studied using a two-by-two factorial design, randomizing at both the patient- and the practice-level. Study staff recruited pregnant women from a diverse set of prenatal care practices in Colorado and Georgia between June 2017 and July 2018. All participants (n = 2087) received a baseline survey of maternal and infant vaccine intentions and attitudes, and two follow-up surveys at least 1 month and 1 year after their infant's birth, respectively. Half of participants (n = 1041) were randomly assigned to receive educational videos through MomsTalkShots, algorithmically tailored to their vaccine intentions, attitudes, and demographics. Since the practice/provider intervention did not appear impactful, this analysis focused on MomsTalkShots regardless of the practice/provider intervention.

RESULTS

By 1 month post-birth, MomsTalkShots increased perceived risk of maternal influenza disease (61% among MomsTalkShots recipients vs 55% among controls; Odds Ratio: 1.61, 95% Confidence Interval: 1.23-2.09), confidence in influenza vaccine efficacy (73% vs 63%; OR: 1.97, 95%CI: 1.47-2.65), and perceived vaccine knowledge (55% vs 48%; OR: 1.39, 95%CI: 1.13-1.72). Among those intending not to vaccinate at baseline, MomsTalkShots increased perceived risk of maternal influenza disease (38% vs 32%; OR: 2.07, 95%CI: 1.15-3.71) and confidence in influenza vaccine efficacy (44% vs 28%; OR: 2.62, 95%CI: 1.46-4.69). By 1 year post-birth, MomsTalkShots increased perceived vaccine knowledge (62% vs 50%; OR: 1.74, 95%CI: 1.36-2.24) and trust in vaccine information from obstetricians and pediatricians (64% vs 55%; OR: 1.53, 95%CI: 1.17-2.00). Among those uncertain about vaccinating at baseline, MomsTalkShots increased perceived vaccine knowledge (47% vs 12%; OR: 6.89, 95%CI: 1.52-31.25) and reduced infant vaccine safety concerns (71% vs 91%; OR: 0.24, 95%CI: 0.06-0.98).

CONCLUSIONS

MomsTalkShots improved pregnant women's and mothers' knowledge and perceptions of maternal and infant vaccines and the diseases they prevent, and offers a scalable tool to address vaccine hesitancy.

TRIAL REGISTRATION

Registered at Clinicaltrials.gov on 13/09/2016 (registration number: NCT02898688).

Maternal health literacy and health numeracy conceptualizations in public health: A scoping review

Despite unprecedented advancement in educational opportunities and access to information, maternal health literacy (MHL) and health numeracy (HN) skills remain low in North America. By enhancing MHL, the educated civic public-those who have the capacity, skills, and knowledge to apply prose and numerical health information-engages more proactively in public health practice. The purpose of this scoping review was to map the existing empirical evidence on MHL to work toward a better understanding of the practical implications for public health. We explored MHL and HN through the following research question: "How are maternal health literacy and health numeracy conceptualised in public health planning, implementation, and evaluation?" First, we employed a five-stage methodological framework for scoping reviews and used PRISMA-P to systematically identify eligible articles. Then, we used thematic analysis and an inductive approach guided by the research aims to identify themes related to how MHL and HN are conceptualised in empirical studies and developed an evidence table. Finally, two different reviewers coded articles using an inductive approach into six themes. We identified 1733 articles through a systematic search of five databases. After screening all the articles, 52 articles were included for thematic analysis. The final themes were: (i) sociocultural demographics; (ii) self-efficacy; (iii) communication; (iv) information seeking and operationalisation; (v) health status; and (vi) reasoning. The research evidence demonstrated limitations concerning the impact of sociocultural background on a mother's recognition of health problems and the extent of which patient-centred care is culturally and linguistically appropriate. The research evidence revealed an opportunity to address the sociocultural linguistic experience of mothers within public health practice. Our research team supports moving away from the biomedical model of evidence-based medicine and adopting evidence-based practice ensures healthcare providers develop a holistic understanding of the maternal health needs of socioculturally diverse mothers.

Using the Health Belief Model to examine travelers' willingness to vaccinate and support for vaccination requirements prior to travel

Data from a survey of 1478 travelers and multistep group structural equation model analysis revealed that the Health Belief Model constructs of cues to action (trust in third-party information sources), perceived severity of and susceptibility to COVID-19, and beliefs about the protection benefits of a COVID-19 vaccine, subsequently elicited willingness to vaccinate and beliefs that others should vaccinate prior to travel and enhanced support for pre-travel vaccination mandates. Also, significant differences in the perceived protection benefits of the vaccine and willingness to vaccinate were found across groups of travelers who travel more or less frequently and those with and without a prior positive test for COVID-19. The study provides a theoretically informed understanding of the dynamics that may enable the success of important health-related travel policy in the wake of COVID-19 and future pandemics and identifies the communication mechanisms that must be leveraged by governments and travel authorities in enforcing policy.

Racial/Ethnic Disparities in Maternal Vaccine Knowledge, Attitudes, and Intentions

OBJECTIVES

Although disparities in maternal vaccine acceptance among racial/ethnic groups are well documented, the reasons for these disparities are unclear. The objective of this study was to describe differences in pregnant women's knowledge, attitudes, beliefs, intentions, and trust regarding maternal and infant vaccines by race/ethnicity.

METHODS

We collected survey data from 1862 pregnant women from diverse prenatal care practices in Georgia and Colorado from June 2017 through July 2018. We performed multiple logistic regressions to determine differences in intentions, knowledge, attitudes, beliefs, and trust by race/ethnicity and calculated odds ratios (ORs) and 95% CIs.

RESULTS

Compared with White women, Black and Hispanic women were less confident in vaccine safety and efficacy and less likely to perceive risk of acquiring vaccine-preventable diseases, report provaccine social norms, indicate having enough vaccine knowledge, and trust vaccine information from health care providers and public health authorities. Black women were the least confident in the safety of the maternal influenza vaccine (OR = 0.37; 95% CI, 0.27-0.49); maternal tetanus, diphtheria, and acellular pertussis vaccine (OR = 0.37; 95% CI, 0.27-0.52); and infant vaccines overall (OR = 0.40; 95% CI, 0.28-0.58), and were least likely to intend to receive both maternal vaccines (OR = 0.35; 95% CI, 0.27-0.47) or all infant vaccines on time (OR = 0.45; 95% CI, 0.34-0.61) as compared with White women.

CONCLUSIONS

Understanding differences in behavioral constructs integral to vaccine decision making among women of different races/ethnicities can lead to tailored interventions to improve vaccine acceptance.

Characterizing the vaccine knowledge, attitudes, beliefs, and intentions of pregnant women in Georgia and Colorado

Vaccine coverage for maternal vaccines is suboptimal; only about half of pregnant women received influenza and Tdap vaccines in 2018. We explored knowledge, attitudes, beliefs, intentions, and trust regarding maternal and infant vaccines among pregnant women. Between June 2017 and July 2018, we surveyed 2196 pregnant women recruited from geographically and socio-demographically diverse prenatal care practices in Georgia and Colorado (56% response rate). Fifty-six percent of pregnant women intended to receive both influenza and Tdap vaccines during pregnancy and 68% intended to vaccinate their baby with all recommended vaccines on time. Attitudinal constructs associated with intention to vaccinate include confidence in vaccine safety (ORs: 16–38) and efficacy (ORs: 4–19), perceived risk of vaccine-preventable diseases (ORs: 2–6), social norms (ORs: 4–10), and trust in sources of vaccine information. Women pregnant with their first child were less likely than women who had prior children to intend to vaccinate themselves and their children, more likely to be unsure about their intentions to receive both maternal and infant vaccines, and less likely to report feeling they had enough knowledge or information about vaccines and vaccine safety (p < .01). This demonstrates an opportunity for vaccine education to increase vaccine confidence and informed decision-making, especially among first-time pregnant women.

Predictors of tetanus, diphtheria, acellular pertussis and influenza vaccination during pregnancy among full-term deliveries in a medically underserved population

OBJECTIVE

To evaluate predictors of vaccination among women who received tetanus, diphtheria, and acellular pertussis vaccination (Tdap), influenza vaccination, and Tdap and influenza vaccinations.

STUDY DESIGN

In a retrospective cohort study of all full-term (≥37 weeks gestation) deliveries between July 1, 2016 and June 30, 2018 at a single, safety-net institution, we used multinomial logistic regression models to compare predictors of vaccination among women who received Tdap only, influenza only, and both Tdap and influenza vaccines.

RESULTS

Among 3132 full-term deliveries, women were primarily non-Hispanic black (67.5%), between the ages of 21-34 (65.3%), and multiparous (76.0%). The rates of only influenza or Tdap vaccination were 10.3% and 21.6%, respectively; 43.3% of women received both vaccines, and 24.9% of women did not receive either vaccine. In the adjusted models, Hispanic ethnicity was positively associated with receipt of all types of vaccination and non-Spanish language interpreter use was positively associated with receipt of Tdap vaccination and Tdap and influenza vaccination. A parity of greater than three and inadequate and unknown prenatal care adequacy were negative predictors of all types of vaccination. Pre-existing hypertension was negatively associated with Tdap vaccination, and HIV-positive status was negatively associated with influenza vaccination and Tdap and influenza vaccination.

CONCLUSION

Compared to the national rate of both Tdap and influenza vaccination (32.8%), a higher proportion of women received both vaccines in our study population. Vaccine uptake may be affected by race/ethnicity, use of interpreter services, parity, pre-existing comorbidities, and prenatal care adequacy. The lower rate of influenza vaccination compared to Tdap vaccination suggests that other factors, such as vaccine hesitancy and mistrust, may be differentially impacting influenza vaccination uptake in our predominantly minority population. Future provider and public health approaches to vaccine promotion should incorporate culturally appropriate strategies that address vaccine-related beliefs and misconceptions.

A systematic review of interventions to improve uptake of pertussis vaccination in pregnancy

BACKGROUND

Maternal pertussis vaccination has been introduced in several countries to prevent pertussis morbidity and mortality in infants too young to be vaccinated. Our review aimed to systematically collect and summarize the available evidence on the effectiveness of interventions used to improve pertussis vaccination uptake in pregnant women.

METHODS

We conducted a systematic search of MEDLINE/PubMed, PMC and CINAHL. Before and after studies and those with a concurrent control group were considered for inclusion. Standardized effect sizes were described as the ratio of the odds to be vaccinated in the intervention group compared with the standard care group and absolute benefit increase (ABI) were calculated.

RESULTS

Six studies were included in the review, of which three were randomized controlled trials (RCTs). Strategies to improve uptake were focused on healthcare providers, pregnant women, or enhancing vaccine access. Healthcare provider interventions included provider reminder, education, feedback and standing orders. Interventions directed at pregnant women focused solely on education. Observational studies showed: (1) the provision of maternal pertussis vaccination by midwives at the place of antenatal care has improved uptake of pertussis vaccine during pregnancy from 20% to 90%; (2) introduction of an automated reminder within the electronic medical record was associated with an improvement in the pertussis immunization rate from 48% to 97%; (3) an increase in prenatal pertussis vaccine uptake from 36% to 61% after strategies to increase provider awareness of recommendations were introduced. In contrast to these findings, interventions in all three RCTs (2 involved education of pregnant women, 1 had multi-component interventions) did not demonstrate improved vaccination uptake.

CONCLUSIONS

Based on the existing research, we recommend incorporating midwife delivered maternal immunization programs at antenatal clinics, use of a provider reminder system to target unvaccinated pregnant women and include maternal pertussis immunization as part of standard antenatal care.

RSV prophylaxis in premature infants

Infants born prematurely before 37 weeks of gestational age (GA) have particular anatomical, immunological and metabolic characteristics that predispose them, even in the absence of diseases at birth, to severe morbidity. Respiratory syncytial virus (RSV) is the leading cause of hospitalization for lower respiratory tract infections (LRTI) in the first year of life, as well as an important cause of respiratory outcomes as recurrent wheezing in industrialized countries or mortality in developing countries. Prematurity is an important risk factor for hospitalization for severe RSV disease, but epidemiological, environmental and demographic risk factors also play a role in RSV infection. Currently, there is no effective antiviral therapy for the treatment of RSV infection, nor the possibility of using maternal immunization or vaccination of children to prevent infection, although numerous preclinical and clinical studies are still ongoing. Passive immunization with palivizumab has been shown to be safe and effective in preventing RSV hospitalization in children at greater risk of contracting a serious infection. Costs associated with palivizumab prophylaxis and its monthly intramuscularly administration has prompted many health institutions of different countries to implement specific recommendations, with the aim of protecting at risk infants for whom RSV infection is likely to cause serious illness or death. The cost-effectiveness ratio of prophylaxis, related to reduce hospitalization costs and the impact of the burden of RSV disease worldwide, greatly affects the drafting and the adoption of specific recommendations and the adherence to them, concerning the passive immunization with palivizumab.

"When you are injected, the baby is protected:" Assessing the acceptability of a maternal Tdap vaccine based on mothers' knowledge, attitudes, and beliefs of pertussis and vaccinations in Lusaka, Zambia

INTRODUCTION

Severe and fatal pertussis infections are concentrated among infants who are too young to be protected through routine vaccinations. Maternal Tdap (mTdap), which is now the standard of care in the US and UK, is considered to be the most effective way to address this gap in preventative care. Little is known about how pregnant women in low-resource settings might view mTdap. To inform strategies for mTdap implementation in these contexts, public health researchers sought to understand knowledge, attitudes, and beliefs toward pertussis and maternal vaccines and assess the barriers to vaccine acceptance.

METHODS

We conducted focus group discussions (FGDs) among mothers who participated in a longitudinal birth cohort study at the Chawama primary health center in Lusaka, Zambia. Since SAMIPS was not a clinical trial, but instead an observational cohort study, registration on clinicaltrials.gov was not required. Trained interviewers conducted the FGDs in January 2016 using a semi-structured interview guide, exploring participants' knowledge, attitudes and beliefs toward pertussis and vaccines. We analyzed the transcripts using Nvivo v.11 software.

RESULTS

Fifty mothers participated across 7 FGDs. Mothers had limited knowledge of pertussis and vaccines, yet expressed generally positive views of vaccinating themselves and their children. Participants conveyed very little vaccine hesitancy around maternal vaccinations, and discussed how they could protect their children's health. Mothers also highlighted barriers and facilitators to vaccine uptake, which included partner involvement, feelings of maternal authority over healthcare decision-making, and community rumors about Western medicine.

CONCLUSION

Mothers viewed vaccinations as an important method to keep their children healthy, despite cultural myths and misconceptions about pertussis and vaccines. FGD results suggest that vaccine acceptability is high in Zambia, which is a critical factor to vaccine uptake. A strategy addressing myths and misconceptions should be prioritized if and when mTdap is introduced across low-resource settings.

Passive and active immunization against respiratory syncytial virus for the young and old

INTRODUCTION

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants worldwide and also causes significant disease in the elderly. Despite 60 years of RSV research and vaccine development, there is only one approved medicine to prevent RSV infections. Palivizumab, a monoclonal antibody (mAb) against the RSV fusion (F) protein, is indicated for preterm infants and children at high-risk for RSV infections. It is an active time in RSV vaccine and mAb development with 14 vaccines and 2 mAbs currently being tested in clinical trials as of 13 February 2017. Active vaccination of women in the third trimester or passive immunization of infants with a mAb are particularly attractive approaches as the most severe disease occurs within the first 6 months of life. Areas covered: Here, we review current approaches for preventing RSV in the young and old, describe proposed clinical endpoints for studies in pediatric and adult clinical trials and highlight results from recent and ongoing clinical studies. Expert commentary: With 16 candidates in clinical development, approval of the first RSV vaccine or mAb for the prevention of RSV in all infants or the elderly is likely to occur in the next five years.

Assessing the Evidence for Maternal Pertussis Immunization: A Report From the Bill & Melinda Gates Foundation Symposium on Pertussis Infant Disease Burden in Low- and Lower-Middle-Income Countries

Implementation of effective interventions has halved maternal and child mortality over the past 2 decades, but less progress has been made in reducing neonatal mortality. Almost 45% of under-5 global mortality now occurs in infants <1 month of age, with approximately 86% of neonatal deaths occurring in low- and lower-middle-income countries (LMICs). As an estimated 23% of neonatal deaths globally are due to infectious causes, maternal immunization (MI) is one intervention that may reduce mortality in the first few months of life, when direct protection often relies on passively transmitted maternal antibodies. Despite all countries including pertussis-containing vaccines in their routine childhood immunization schedules, supported through the Expanded Programme on Immunization, pertussis continues to circulate globally. Although based on limited robust epidemiologic data, current estimates derived from modeling implicate pertussis in 1% of under-5 mortality, with infants too young to be vaccinated at highest risk of death. Pertussis MI programs have proven effective in reducing infant pertussis mortality in high-income countries using tetanus-diphtheria-acellular pertussis (Tdap) vaccines in their maternal and infant programs; however, these vaccines are cost-prohibitive for routine use in LMICs. The reach of antenatal care programs to deliver maternal pertussis vaccines, particularly with respect to infants at greatest risk of pertussis, needs to be further evaluated. Recognizing that decisions on the potential impact of pertussis MI in LMICs need, as a first step, robust contemporary mortality data for early infant pertussis, a symposium of global key experts was held. The symposium reviewed current evidence and identified knowledge gaps with respect to the infant pertussis disease burden in LMICs, and discussed proposed strategies to assess the potential impact of pertussis MI.

Maternal Tdap vaccination: Coverage and acute safety outcomes in the vaccine safety datalink, 2007-2013

INTRODUCTION

Since October 2012, the combined tetanus toxoid, reduced diphtheria toxoid, acellular pertussis vaccine (Tdap) has been recommended in the United States during every pregnancy.

METHODS

In this observational study from the Vaccine Safety Datalink, we describe receipt of Tdap during pregnancy among insured women with live births across seven health systems. Using a retrospective matched cohort, we evaluated risks for selected medically attended adverse events in pregnant women, occurring within 42 days of vaccination. Using a generalized estimating equation, we calculated adjusted incident rate ratios (AIRR).

RESULTS

Our vaccine coverage cohort included 438,487 live births between January 1, 2007 and November 15, 2013. Across the coverage cohort, 14% received Tdap during pregnancy. By 2013, Tdap was administered during pregnancy in 41.7% of live births, primarily in the 3rd trimester. Our vaccine safety cohort included 53,885 vaccinated and 109,253 matched unvaccinated pregnant women. There was no increased risk for a composite outcome of medically attended acute adverse events within 3 days of vaccination. Similarly, across the safety cohort, over a 42 day window, incident neurologic events, thrombotic events, and new onset proteinuria did not differ by maternal receipt of Tdap. Among women receiving Tdap at 20 weeks gestation or later, as compared to their matched controls, there was no increased risk for gestational diabetes or cardiac events while venous thromboembolic events and thrombocytopenia were diagnosed within 42 days of vaccination at slightly decreased rates.

CONCLUSION

Tdap coverage during pregnancy increased from 2007 through 2013, but was still below 50%. No acute maternal safety signals were detected in this large cohort.